A class has 3 sections. Here is a summary of the scores on the final exam.
Average SD Number of Students
Section 1 68 9 20
Section 2 75 9 25
Section 3 60 9 32
Find the average score of all the students in the class.
Mean = ∑x/n --> n(mean) = ∑x
(68*20) + (75*25) + (60*32) = ?
Divide that by 20 + 25 + 32 = ?
Thanks I got it
To find the average score of all the students in the class, we need to calculate the weighted average of the section averages, taking into account the number of students in each section.
The weighted average formula is:
Average = (Sum of (Average * Number of Students)) / Total Number of Students
Let's calculate it step by step:
1. Calculate the sum of (Average * Number of Students) for each section:
Section 1: (68 * 20) = 1360
Section 2: (75 * 25) = 1875
Section 3: (60 * 32) = 1920
2. Calculate the total number of students:
Total Number of Students = 20 + 25 + 32 = 77
3. Calculate the weighted average by dividing the sum of (Average * Number of Students) by the total number of students:
Weighted Average = (1360 + 1875 + 1920) / 77
4. Calculate the final answer:
Weighted Average = 5155 / 77 ≈ 66.95
Therefore, the average score of all the students in the class is approximately 66.95.